A variety of different devices have been used to retract delicate tissue during surgical procedures. One such device is illustrated in United States Patent Publication Number 2010/0010315 (“Mangiardi I”), which is incorporated herein by reference in its entirety. Mangiardi I shows two general versions of a retractor for delicate tissue. One version is a closed-channel retractor in the form of a tube (see, e.g., Mangiardi I FIG. 3), and the other is an open-channel retractor in the form of a curved channel (see, e.g., Mangiardi I FIG. 23).
FIG. 1 of this application illustrates a soft tissue retractor system such as found in Mangiardi I. The retractor system includes a hollow retractor 100, and an introducer 102 that is selectively inserted into the retractor 100. The retractor 100 and/or introducer 102 may include a handle 104 to facilitate manipulation and placement of the retractor system, and a lock to hold the introducer and retractor together. The illustrated handle 104 is molded integrally with the retractor 100, but it may be a separate part. The handle 104 may be configured to connect to a clamp 106, such as the standard surgical clamp 106 shown in FIG. 1. In this example, the handle 104 has a ridge 108 that fits into a corresponding groove 110 on the clamp 106, to prevent relative rotation between the two when engaged. Modifications to this design are described in Mangiardi I.
A retractor system such as shown in FIG. 1 is often used by inserting the introducer 102 into the retractor 100 and locking it in place, so the two can be moved and manipulated as a unit. The combined retractor system is inserted into the patient's body and moved to the surgery site, and then the introducer 102 is unlocked and removed to permit access to the site through the retractor 100. When the unit is in place (either before or after the introducer 102 is removed), the handle 104 may be locked to a clamp 106 to hold the retractor 100 in place. An example of this procedure is shown in FIGS. 16-20 of Mangiardi I. Surgeons using the Mangiardi I retractor sometimes do not use a clamp to hold the retractor at the surgery site, and often manually manipulate the retractor to access different parts of the surgery site during the surgical procedure. The retractor system and the retractor may be manipulated by holding the proximal ends of the introducer or retractor or by holding the handle.
The device shown in Mangiardi I may have a transparent introducer 102 and/or retractor 100, and surgeons using such devices advantageously use the transparent introducer and retractor to manually guide the unit to the surgery site. While it has been found that visual guidance by looking through the introducer 102 is very beneficial, it also has been found that some form of additional guidance or navigation may be desired in some cases. For example, in some cases, surgeons have used a probe or guide wire (a narrow elongated rod) to guide the movement of the retractor system. In such cases, the probe is advanced to the surgery site, and then the interlocked retractor system is slid over the probe until it reaches the surgery site. This is facilitated by the inclusion of a hole at the tip of the introducer that fits around the probe. If the hole through the tip of the introducer is absent, this method cannot be used. This type of system is described in United States Patent Publication Numbers 2008/0109026 and 2009/0048622, which are incorporated herein by reference. These references also show an alternative construction, in which the retractor is not locked to the introducer.
It has been found that some surgeons using the above procedure may use a probe that is integrated into a computer navigation system. For example, the probe may include a so-called “starburst” or the like, on the probe's proximal end (i.e., the end opposite the distal end that is inserted to the surgical site). This and other navigation systems are known in the art. For example, frameless navigation systems and other computerized guidance systems and methods are described in U.S. Publication No. 2001/0027271 (which is incorporated herein by reference in its entirety) and others, and are commercially available from companies such as Medtronic, Inc., Stryker, BrainLab, AG, and GE Healthcare. As used herein, “computerized guidance” encompasses any method of guiding a device to or at a surgical site that relies on computer visualization and/or control. Mangiardi I briefly notes the possibility of using stereotactic guidance or navigation in conjunction with a surgical retractor, but does not illustrate or describe this procedure or any apparatus for accomplishing this objective.
While computerized surgical guidance systems are well-known, a number of limitations exist with respect to their use with retractor systems, and particularly with systems like those shown in Mangiardi I. For example, while some surgeons use computerized guidance to direct a probe to the surgery site, and then slide the retractor system over the probe to the site, the movement of the retractor may be somewhat imprecise and the process can be unduly cumbersome. This method also is not available if the retractor system does not have a through-hole that fits over the probe (due either to the absence of a hole or a hole that is too small). In addition, the probe does not provide a view of the tissue through which it is advanced, so there is no visual means to perceive and avoid critical tissue (e.g., major blood vessels or nerves) when inserting a probe before inserting a retractor/introducer system. Also, the small-diameter probe may sever delicate tissue cells, such as grey or white brain matter, rather than moving the cells aside and passing between them as would be expected to happen when advancing the retractor system.
United States Patent Publication Number 2013/0066154 (“Mangiardi II”), shows examples of systems for integrating a navigation probe into a surgical introducer. For example, FIGS. 1-6 of Mangiardi II shows a navigation probe that is secured to the inside of a pre-existing introducer by resilient means, such as rubber plugs or O-rings. Another version of the Mangiardi II device uses a slip fit (e.g., FIGS. 7-8), and still another version uses an arm to hold the probe down inside the introducer (FIG. 9). Still other versions mount the navigation device outside the introducer, to an arm that is connected to the retractor assembly (FIGS. 10-11). While these systems may provide suitable performance, they also have certain potential shortcomings. For example, resilient plugs may slip in the presence of fluids, a slip fit requires careful monitoring to ensure proper positioning, an arm as shown in FIG. 9 to hold the probe in place requires the probe to be modified to include a surface against which the arm pushes, and locating the navigation device outside the introducer complicates the correlation between the navigation device and the tip of the introducer or retractor.
United States Patent Publication Number 2012/0071748 shows another example of a system for integrating a navigation probe into a surgical introducer. In this case, the probe is retained in a narrow channel through the introducer, and held in place with a threaded locking screw. The locking screw adds an additional potentially-removable part to the operating theater, and therefore this reference adds a separate retaining device (see FIG. 7B) to prevent the locking screw from being removed.
It has been found that there still remains a need to provide alternative apparatus and methods for coordinating the use of guidance systems with surgical introducers.